The present invention relates in general to electrically driven hand-operated tools such as hand-operated drilling, milling or sawing machines and the like, preferably a combination tool for a home repairman, and in particular it relates to a tool having a housing defining a handle and within the housing a driving electromotor and means for presetting and/or adjusting various modes of operation of the tool such as the rotary speed, the direction of rotation and the torque.
In known tools of this type the presetting and adjusting switches are in the form of rotary control knobs or toggle switches mounted on the housing of the tool. In contemporary designs of such tools the tendency is to provide for the user more and more possibilities for setting various operations of the driving electromotor, such as the rotary speed, the rotary direction and the like in order to adjust the electrically driven tool to different working conditions in an optimum manner thus to provide for an improved utilization of the tool. Such increased setting possibilities considerably improve the result of the working operation and the work done by such tools has a better quality. Nonetheless, the multiplicity of such setting possibilities necessitates an excessive number of control elements which confuses frequently the user and may cause quite opposite results than intended, namely that by faulty adjustments and by the lack of possibility to quickly check the actual setting on the tool during the working process there may arise troubles of breakdowns which may endanger both the user and the function of the tool and produce impaired working results. As a consequence, due to the susceptibility of conventional hand-operated tools of the aforedescribed type to misadjustments or to errors in setting the working condition of the driving electromotor, the user is discouraged by the large number of control possibilities and does not make any use of them either at all or uses the setting possibilities in an insignificant manner only.